In a study published in the journal Toxicology, researchers examined the effects of exposing human colon cancer cell line (HTC116) titanium dioxide food additives in vitro. “In the absence of cytotoxicity, E171 was accumulated in the cells after 24 hours of exposure, increasing granularity and reactive oxygen species, inducing alterations in the molecular pattern of nucleic acids and lipids, and causing nuclei enlargement, DNA damage and tubulin depolymerization,” the scientists wrote. Researchers removed the additive from the culture, then examined the results 48 hours later. They found, “The removal of E171 was unable to revert the alterations found after 24 h of exposure in colon cells. In conclusion, exposure to E171 causes alterations that cannot be reverted after 48 h if E171 is removed from colon cells.”

Inventory: Low inventory of mainstream producers, it is expected that the overall size of spot inventory today is low, and there is less stock in mainstream factories.2. Mentality: the buyer has to prepare goods in advance, and the new order price is slightly less willing to purchase in bulk; Because the seller's inventory is small, the manufacturer has no willingness to reduce the price of sales, and the demand for new orders in the market is relatively large.Trend: The load of titanium dioxide enterprises is stable, the willingness to ship at low prices is not strong, and the downstream buyers still have inventory digestion, and the intention to supplement orders in the short term is limited. It is expected that the market price of titanium dioxide is stable today, and the market trading atmosphere is more general.
According to the feedback of manufacturers, the new orders of mainstream factories maintain stable prices, and the overall new volume of the market is limited. On the demand side, the terminal basically had batch replenishment last month, and the purchase intention of new orders was low; On the supply side, mainstream manufacturers normally produce and deliver goods, and the actual output of the industry is stable. Most factories quote a new price of 17,000 yuan/ton or more market negotiation range reference 16000-17200 yuan/ton, plastics and papermaking related downstream feedback part of the tight model price is higher. Recent titanium dioxide raw materials are expected to weaken, titanium dioxide price support is relatively limited, comprehensive market factors, the current titanium dioxide market many buyers hold a wait-and-see mentality.

Different dermal cell types have been reported to differ in their sensitivity to nano-sized TiO₂ . Kiss et al. exposed human keratinocytes (HaCaT), human dermal fibroblast cells, sebaceous gland cells (SZ95) and primary human melanocytes to 9 nm-sized TiO₂ particles at concentrations from 0.15 to 15 μg/cm² for up to 4 days. The particles were detected in the cytoplasm and perinuclear region in fibroblasts and melanocytes, but not in kerati-nocytes or sebaceous cells. The uptake was associated with an increase in the intracellular Ca²⁺ concentration. A dose- and time-dependent decrease in cell proliferation was evident in all cell types, whereas in fibroblasts an increase in cell death via apoptosis has also been observed. Anatase TiO₂ in 20–100 nm-sized form has been shown to be cytotoxic in mouse L929 fibroblasts. The decrease in cell viability was associated with an increase in the production of ROS and the depletion of glutathione. The particles were internalized and detected within lysosomes. In human keratinocytes exposed for 24 h to non-illuminated, 7 nm-sized anatase TiO_2, a cluster analysis of the gene expression revealed that genes involved in the “inflammatory response” and “cell adhesion”, but not those involved in “oxidative stress” and “apoptosis”, were up-regulated. The results suggest that non-illuminated TiO₂ particles have no significant impact on ROS-associated oxidative damage, but affect the cell-matrix adhesion in keratinocytes in extracellular matrix remodelling. In human keratinocytes, Kocbek et al. investigated the adverse effects of 25 nm-sized anatase TiO₂ (5 and 10 μg/ml) after 3 months of exposure and found no changes in the cell growth and morphology, mitochondrial function and cell cycle distribution. The only change was a larger number of nanotubular intracellular connections in TiO₂-exposed cells compared to non-exposed cells. Although the authors proposed that this change may indicate a cellular transformation, the significance of this finding is not clear. On the other hand, Dunford et al. studied the genotoxicity of UV-irradiated TiO₂ extracted from sunscreen lotions, and reported severe damage to plasmid and nuclear DNA in human fibroblasts. Manitol (antioxidant) prevented DNA damage, implying that the genotoxicity was mediated by ROS.

The mineral appears to have low skin penetration, but it is a greater concern when inhaled frequently over time.